True or False: Volcanoes at the edges and in the centre of oceanic plates are indistinguishable.?

It is false.





Volcanoes at the edge melt continental crust as the magma moves towards the surface. This crust contains silica which acts a bit like cornflour, it thickens the magma. Instead of it being runny as it is in Hawaii it becomes thick.





This results in two things, first it builds volcanoes up into classic cone shapes as the lava doesnt flow, so just piles up.





Secondly, as the magma is thick, gases are unable to escape easily from it, unlike in oceanic volcanoes.l These leads to build up of gases in the magma, which eventually cause so much stress they explode like an over inflated ballon.





For example the eruption of Mt St Helens in the NW USA in the early 1980's.True or False: Volcanoes at the edges and in the centre of oceanic plates are indistinguishable.?
False, I think. Mid plate volcanoes are usually shield volcanoes, which are formed by the eruption of low-viscosity lavas that can flow a great distance from a vent, but not generally explode catastrophically. The Hawaiian volcanic chain is a series of shield cones, and they are common in Iceland, as well.